Twenty-five years of intensive study has revealed a Shortgrass Steppe (SGS) ecosystem for which, despite chronic water stress, periods of severe drought, and intensive grazing by large herbivores, the essential ecological structure and functioning remain intact. With global change, however, a range of conditions is anticipated to develop far outside those experienced during the last several thousand years. Forecasting how the SGS will respond depends on understanding of key ecosystem drivers, including climate, physiography, biotic structure, natural disturbance, and human land use. The resilient ecosystem, bounded within natural variation but interrupted by human influence, may be supplanted by an unfamiliar one, with humans playing a much more direct role. The goal of the proposed research is to test the limits of resilience, function and structure of the SGS, by both continuing past work and by experimentally manipulating factors in new experiments that are known from previous work to be important. Multiple temporal scales of change and a combination of long-term monitoring, short- and long-term experiments will enable forecasts of the impacts of global change on the SGS. Experiments will involve manipulating factors that will most likely change in the future, and selecting ecological attributes and interactions previously identified either as vulnerable to change or likely to influence multiple other interactions. The project is organized into research groups that focus on biotic interactions and ecosystem processes, with multiple interdisciplinary studies united by cross-LTER studies, data synthesis and modeling.
Besides publishing hundreds of peer-reviewed journal articles and scholarly books in outlets with global reach, including a recent SGS synthesis volume, SGS-LTER impacts Colorado State University, communities and land users within Colorado, and beyond. Activities include outreach to ranchers, non-governmental organizations and land managers (especially from the U.S. Department of Agriculture); a large educational program integrated across K-12; involvement by hundreds of undergraduates as field crew, independent study students, and REU students; and an active graduate program. Much SGS education work reaches out to groups underrepresented in STEM disciplines. The ability to provide outreach is vastly improved upon recent completion of new classroom building at the field site. SGS maintains a proactive Information Management system that works to improve access to long-term data sets and the project web page is being redesigned to facilitate data access.
Between 2008 and 2012, the Shortgrass Steppe Long-Term Ecological Research project has continued over 30 years of basic and applied research on the ecology of the shortgrass steppe rangelands northeast of Fort Collins, CO. We have trained over twp dozen undergraduate and graduate students during this funding cycle, provided educational opportunities for area K-12 teachers, and worked with local partners to increase our understanding of potential impacts that may result from global climate change. Graduate and undergraduate students receiving training through this program have gone on to work in natural resources and agricultural science research and management as well as K-12 teaching. Teachers participating in short-term field research have brought a hands-on experience of the scientific method to their middle and high school classes, sparking more interest in the resources that are vital to the local economy. Our scientific and social science research has provided basic knowledge on ecosystem function for the scientific community and specific information to local ranchers on what they might expect from land use changes, population pressure on the existing open lands, energy development and global climate change. Our scientists have reported new research findings in over 150 journal articles over the duration of this award. Their scholarly work is also represented more than a dozen book chapters and a book covering the scope of research on the Colorado Shortgrass Steppe (Ecology of the Shortgrass Steppe: A Long-Term Perspective). Researchers at all levels have presented their research at scientific meetings, technical workshops and to local ranching groups. The major focus of the project has been to relate changes in the short grass steppe ecosystem, the semi-arid portion the the American Great Plains. This ecosystem isdominated by warm-season grasses that are short in stature (~10 cm or less) and that are adapted to a combination of intermittant rains, periods of more persistent drought, and grazing by large herbivores (historically bison, currently livestock). In particular, we have hypothe4sized that annual patterns of rainfall have changed even as the total amount has not, leading to potential changes in the timing of major annual events like seed set of grasses, the amount of carbon stored underground, and the species composition of the grasslands.
